HOW TO: TBI Flowtech Headers & Y-Pipe on a Vortec + 3” SI/SO Exhaust for Burbs

[99'Subourbon]

Although the stock y-pipe on my model year is better than previous years, it's still tiny, and flattened badly. I wanted.to get what performance I could out of the burb, not just sound. It's my understanding that the exhaust in our motors is the largest restriction to its abilities, and how retarded the tune is from factory (pun intended). I don't plan on getting rid of her, so I'm putting money into it that I intend to be future proofed for later upgrades (get it done right, the first time).

I'll take a pic of the stock pipe tomorrow for comparison.

I'm considering buying a Oregon performance, or truetech, master performance rebuild kit for the tranny - I think that's where I'm losing power.

 

[99'Subourbon]

http://www.gmt400.com/forum/showthr...etup-do-LS-engines-like-True-dual-or-2-into-1
It's the same as when I got it. I found out months later that it was true duals all the way back. No x-over, except when they meet at the di/do muffler. But it still has stock manifolds, so that's why I want to go for shortys, since it's custom all the way up until the manifolds.

It's hard to tell on a phone, but yours seems to idle louder then mine, for not having headers. Maybe because mine has less back pressure. I really like the way your exhaust sounds, and if I could convince myself a baffled muffler isn't going to hinder the flow, I would have went that route. If you get headers, it'll sound sick.

To answer that posts question, I think what's "best" is a dual pipe system that has an x-pipe. Helps with scavenging, and balance and smoothing out the exhaust pulse. They tend to sound better too.

 

[Parentnoia]

Well I'm considering making my exhaust a little bit modular. Buy a bunch of ball socket flanges and piece it together to get the best result. My main idea I have thought about is an h-pipe into dual si/so mufflers.

I'll take a video tomorrow when I leave for class so you can hear what it sounds like at normal operation.

Also, I'd love to tell you what muffler I have, but from underneath, it's blank.

 

[Jorge6.5]

Nice exhaust install! Any improvment in performance?

 

[99'Subourbon]

definitely an improvement, all around. 60+ the pickup is a whole lot better, and I have a lot more off the line now too. I didn't try it with just exhaust before installing my tune though, so that impression is from both.
However, I think my 1-2 gears are slipping, and is where I think I am losing more power than I should - considering a tranny performance rebuild.

 

[Colorado2500]

So you definitely recommend the afterburner stuff? How is the spark plug clearance with the headers? I was looking at the cheaper flowtech stuff, but they have bad reviews on summit, so I'm not sure.

 

[ccreddell]

Im looking for something like this on a lowered 2WD. So, I was wondering how well it tucks up under the truck.

 

[99'Subourbon]

So you definitely recommend the afterburner stuff? How is the spark plug clearance with the headers? I was looking at the cheaper flowtech stuff, but they have bad reviews on summit, so I'm not sure.

I have no issues at all with spark plug clearance. Some of them you have to come at an awkward angle on, but I put them in and took them out again after having the headers in place. It's easier than with the stock manifold.

As far as recommendation goes, these are by far the best fitting headers I have installed. And gaskets/flange are seeming to seal really well. There is always variances in production with these types of things, but I would definitely recommend them. I think its the best bang for your buck that you can get.

Im looking for something like this on a lowered 2WD. So, I was wondering how well it tucks up under the truck.

I'll grab another picture for you this evening. Where the y-pipe crosses over to the passenger side, is the lowest point in the setup, and it is above the frame of chassis looking at it from the side.

 

[superdave]

I like the way that worked out. The PO on my 97 put a si/do Flowmaster on with a 3 inch inlet (I guess it was what the muffler shop had laying around). It has nice 2 1/4 duals from that out the back. I see no need in replacing that. I could use a single 3 inch converter with that. Not exactly legal, but close. Anybody welded on a fitting for EGR on headers?

 

[99'Subourbon]

Here is the pic of the flange of the headers to the y-pipe on the driver side, which is the lowest point. The flange is about 1/4" below the bottom of the frame.

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